Questions You Always Wanted to Ask (but didn't want to look stupid)     Why does my stomach rumble?   You don't always hear the noises that your stomach makes. The thick, strong muscles of the stomach continually squeeze and churn the food in it. When your stomach is empty, the noises of the muscles contracting and relaxing are amplified by the emptiness of the stomach. Remeber the saying ' empty vessels make the most sound'? The rumbles usually stop after you have eaten.   Can you swallow upside down?   When you swallow, the muscles behind the food contract automatically, pushing the food along the esophagus, and forcing it down into the stomach. This squeezing action is known as peristalsis. When you swallow, the small flap of tissue which you can see hanging down at the back of your throat when you look in a mirror, closes off the entrance to your windpipe. At the same time another flap closes the tube leading to your nose. So, yes, you could swallow upside down without choking.   How small is my small intestine?   Your small intestine is actually very long - about four times as long as your body! It is coiled and folded to fit inside your abdomen. The beginning of the small intestine is called the duodenum, which, with the help of digestive juices from the pancreas and bile from the gall bladder, continues to break down the food from the stomach into substances the body can use.   How large is my large intestine?   Your large intestine is really rather small in comparison to the small intestine, but because it is generally wider, it is called the large intestine.Its function is to absorb water and the remaining useful material in your gut. As this happens the material becomes drier and solid forming faeces, which is stored in the last part of the large intestine, the rectum, before being expelled via the anus.   Do people really drink urine?   Most of us would have to be very thirsty before we would contemplate drinking our own urine! However, two Indian Prime Ministers did it every day, believing it to be very beneficial to their health. It is an ancient yogic belief that to drink your own mid-stream urine - a custom called 'amaroli' - would help in meditation. Your body makes about a small glassful of urine per hour. This contains 95 percent water and some proteins, enzymes, vitamins, salts, uric acid, prostaglandins and melatonin. Melatonin has been found to be a mild sedative, giving a feeling of emotional balance, feelings of elation and even some pain relief. So this may be the reason that yogis believe it is good to drink your own urine.   Why do we get hiccups?   Sometimes if you eat too fast, or eat very hot or very cold food, your diaphragm goes into a spasm, making you breathe in very quickly, and causing your vocal chords to snap shut. This causes the noisy hiccup we find difficult to stop.   How can you stop hiccups?   There are many supposed remedies for curing the hiccups, from giving the person a fright to drinking upside down from a glass of water. Breathing into a paper bag, or drinking slowly from the far side of a glass seem to the most effective remedies.   How much food does a stomach hold?   An adult's stomach holds a bit less than a litre of food, although it can stretch and hold more after a large meal.   How long does it take to digest a meal?   The digestion of an average meal is complete after six to ten hours. This depends on the types of foods eaten. The remaining indigestible materials pass into the large intestine and stay there for about 15 hours before being expelled from the body.   Do carrots really help you see in the dark?   Nobody can see in pitch dark, but good night vision depends on vitamin A. Carrots contain a substance called carotene, which the body uses to make vitamin A, so carrots ensure good night vision, altough too much vitamin A can be poisonous!   How can a snake swallow something larger than its head?   Snakes can make their mouths many times larger, by dislocating their jaws. Their skin can stretch enormously, making it possible for them to swallow animals like an antelope, which are physically much larger than themselves.

Bibliography Bunce, G. The Human Body (London: New Holland, 1993) Drillsma; Goodman. What's Inside the Human Body? (Hertfordshire: Simon & Schuster, 1993) Ganeri, A. Animal Food (London: Gollancz, 1992) Kruszelnicki, K. Bizarre Moments in Science (Sydney: ABC, 1993) West, D. Answers to Questions You Always Wanted to Ask (London: Simon & Schuster, 1991)